Out of the Ashes

Get up and meet Strickland and Gould near the convoy. You may want to explore the area before boarding your vehicle (there's a secret collectible here). In any case, load up on weapons that do damage so you can be well outfitted later.

Ride the vehicle and shoot liberally at anything that threatens you. Since you have infinite ammunition, that should be easy. If it moves, it dies.

An alien robo-phallus will destroy your APC, and automatically boot you off the gun-ride. Cloak and head for the building occupied by the Ceph.

Your goal is to enter the building and ride the lift up to secure an overwatch point. Take the C4 explosives in the hotel lobby if you need them. For the most part, you may not need any of that at all.

Ride the lift up and explore while cloaked. You can locate the destroyed hallway leading to the emplaced machinegun — should you take it, you can start killing the Ceph that patrol the overwatch room with little trouble.

Don't linger at the emplacement, because enemies can come at you from behind. Take the gun and head back to the hallway entrance to lure enemies into your killzone. Enemies cannot jump through the window where the gun was pointing out from.

To deal with the Ceph Gunship, lower you VISOR and mark it for an airstrike. That done, you can move on to the next zone.

Sneak through the next zone (and to the exit). Locate the top of the greenhouse and aim for the tactical point which details "Ledge Grab".

Get up onto the square greenhouse near the Ledge Grab tactical point and aim for evading the Ceph Devastator and heading for the marked rooftop. Once you reach it, the mission ends.